Mobile devices such as mobile phones, personal digital assistants (“PDAs”), portable audio and/or video players and other handheld devices have transformed the modern world by providing many practical mobile services to users wherever they may travel. One such mobile service is the reception of mobile multimedia (“MM”) content. Because of the portable nature of mobile devices, mobile MM content is generally broadcast to users over the air using mobile MM signals. One of the most common types of MM content carried by the mobile MM signals is digital television content. However, it is recognized that any type of digital content may be carried by mobile MM signals.
Accordingly, a variety of standards has emerged and continues to evolve with regard to the transmission of and receipt of mobile MM signals. One such standard is the Digital Video Broadcasting-Handheld (“DVB-H”) standard. One having ordinary skill in the art will recognize that the DVB-H standard is one standard of several standards associated with the Digital Video Broadcasting suite of standards that also govern, among other things, the transmission and receipt of terrestrial and satellite signals. Other mobile MM signal standards include, but are not limited to, MediaFLO by Qualcomm, Digital Multimedia Broadcasting (“DMB”) and Terrestrial Integrated Services Digital Broadcasting (ISDB-T).
As recognized, mobile MM signals consist of one or more MM streams that are compressed, time division multiplexed, modulated and broadcast at a predetermined frequency. Generally, each service provider is allocated one or more frequencies through which it may broadcast mobile MM content. Because each mobile MM stream is time division multiplexed, the content from each stream appears in a given mobile MM signal at periodic intervals. Each appearance may be termed a burst. To capture a given burst of a desired mobile MM stream, a mobile MM receiver uses its mobile MM tuner to selectively tune into a desired frequency along which the mobile MM signal is broadcast and to selectively listen and capture a specific time slice of the broadcast mobile MM signal. Other bursts from one or more additional mobile MM streams, however, may also be captured based on the size of the time slice. It is recognized that the longer the time slice, the more bursts form other additional mobile MM streams may be captured.
After capture, the mobile MM content from the time slice is demodulated by the MM receiver. The demodulated mobile MM content from the time slice includes one or more IP datagrams. After demodulation, the IP datagrams corresponding to the desired mobile MM stream are stored in memory prior to display. If display is desired in real time, the storage may be temporary and used for timing purposes. The other IP datagrams corresponding to other captured bursts from other additional mobile MM streams are discarded. IP datagram are distinguished, as known in the art, by IP address information contained in the header of each IP datagram. Those having ordinary skill in the art will recognize that because the demodulated multimedia content is in the form of IP datagrams, any type of digital content may be broadcast as IP packets (i.e., the same format used to transfer data over the Internet). For example, video streams, web pages, music files, and games are just some examples of digital content that may be broadcast using mobile MM signals.
After a given capture, one or more components of the mobile MM receiver are selectively placed into a low power state to conserve power on the mobile device until the next burst is broadcast and available. Just prior to the next burst, the mobile MM receiver is selectively turned on and provided information as to when to capture the next time slice containing mobile MM content associated with the desired mobile MM stream.
During an initial capture of a mobile MM stream, for example, a user initially powers up a mobile device and then selects a given mobile MM stream by inputting a current mobile MM stream command input. The mobile MM receiver and tuner may be selectively controlled using frequency information and timing information stored on the mobile device. In one embodiment, the mobile device may be preprogrammed to listen to a predetermined frequency corresponding to the service to which a user subscribes while timing information is obtained from an initial capture (e.g., as part of Electronic Service Guide (“ESG”) data broadcast in the mobile MM signal). In another embodiment, the mobile device may be preprogrammed to contain both predetermined frequency and timing information. Other suitable techniques are also recognized. To capture subsequent bursts, the mobile MM receiver is selectively turned on just prior to the burst being available by keeping track of slice time information contained in a previous burst where the slice time information represents an amount of time before a subsequent burst of the same mobile MM stream.
After a user selects a mobile MM stream, the process of placing one or more components of the mobile MM receiver in a low power state and turning it back on prior to capture of a subsequent burst is transparent to the user. However, when a user desires to select a different mobile MM stream (e.g., when a user changes channels of digital TV), an undesirable zapping delay is experienced. The zapping time corresponds to the amount of time necessary for at least one of: (i) the mobile device to determine the frequency and time slice information of the newly selected mobile MM stream, (ii) the mobile MM receiver (e.g., tuner) to wait until the time slice is available on the mobile MM signal and to subsequently acquire or capture the time slice, (iii) the mobile MM receiver (e.g., demodulator) to demodulate the captured time slice, (iv) a controller to identify the IP datagrams corresponding to the proper burst (while discarding other IP datagrams), (v) the mobile MM receiver, controller or decoder to perform any error correction, (vi) the decoder to decode the burst, and (vii) the display of the burst representing at least a portion of the newly selected mobile MM stream. Due to the period and length of each time slice and burst and further due to the layers of complexity involved in error correction and identifying the appropriate IP datagrams, the combined zapping delay can be on the order of 5-7 seconds depending on the service provider network configuration and the design of the mobile device.
As recognized, the zapping delay results in an undesirable user experience in a mobile MM environment. Accordingly, a need exists for reducing the zapping delay and making a user's experiences in mobile MM environments more desirable. A further need exists to keep the overall power consumption of the mobile device to a minimum while providing the desirable mobile MM environment.